This invention relates generally to turbine engines, and, more particularly, to turbine engines including flow restrictors.
A turbine engine typically includes a compressor assembly and a combustor assembly, each including a plurality of bleed air ports. The bleed air ports extend through a casing surrounding the compressor and combustor, and in operation, a portion of the compressed air flowing through the compressor is extracted through a bleed air supply system (BASS) attached to the bleed air ports. The bleed air may be used, for example, by an environment control system (ECS) to provide compressed air in the cabin of an aircraft or to aid in restarting an engine which has been shut down.
In known engines, flow restrictors are installed in the bleed air ports. Each flow restrictor has an internal shape similar to that of a venturi tube which restricts an amount of airflow being extracted and maintains and/or increases the pressure of the airflow exiting the bleed ports into bleed ducts. The bleed ducts channel the airflow from the bleed ports and retain the flow restrictors within the bleed ports. Over time, vibrations generated while the engine operates may cause the bleed ducts to loosen from the bleed ports resulting in a misalignment of the associated flow restrictor. Additionally, bleed ducts may be removed from bleed ports for maintenance, and the installed flow restrictors may fall from the engine and be easily damaged.
Other engines include flow restrictors which are retained within the bleed ports with intricate retaining systems. Such retaining systems permit the bleed ducts to attach to the bleed ports while permitting bleed air to pass through the flow restrictors. Such retaining systems are expensive and over time may loosen as a result of engine vibrations.